▎ 摘　　要

NOVELTY - Method for preparing nitrogen-doped graphene activated carbon material, involves (a) mixing melamine and L-cysteine, and ball-milling to obtain a precursor, and (b) carbonizing in an inert atmosphere, and cooling to room temperature to obtain the material. USE - The method is useful for preparing nitrogen-doped graphene activated carbon material used as cathode material for lithium sulfur battery (all claimed). ADVANTAGE - The method adopts simple and economical process, and is easy to operate and suitable for industrial production, and the prepared nitrogen-doped graphene activated carbon material has large specific surface area and pore volume. The lithium-sulfur battery based on this material has long cycle stability performance, excellent rate performance, and high charge-discharge reversible specific capacity.